Again, we're taking continuity FAR more seriously than CBS do. It boggles my mind that they did that "previously on..." harking all the way back to "The Cage", which it's entirely different look, technology, characterisation etc.
When Roddenberry spoke about the change in Klingons for TMP, he said something like [I'm paraphrasing, but this was his assertion]
"The Klingons in TOS are intended to look exactly like they do in TMP; just ignore the differences in makeup".
So going by that tradition started by Roddenberry with TMP, we use that philosophy in reverse and simply imagine that the stuff in the Cage we saw in that "previously on..." was supposed to look like what we now see in DSC.
Amen, I agree with you. Now, can you baptism me and let me join your Church of trek?
But, seriously, I agree with you. I treat Discovery as an alternate Universe.
And while I can respect that position (as I've told BillJ that I respect his position on it), I still disagree with it....and will keep trying to change minds
Taking Roddenberry's idea about the TMP Klingons a step further, we can use his TMP philosophy of "Klingons are intended to look the same in TOS and TMP" to also imagine that the look of DSC is supposed to look like TOS. So ignoring the look, nothing presented on DSC so far concerning the characters shown and the stories told directly contradicts TOS, so I certainly see DSC directly leading to TOS -- which is what the showrunners has said is the intention.
Therefore to that end, considering the stories and characters in DSC will lead us to TOS, I can absolutely see this show as being part of the same universe as TOS. If someone has an issue with the differences in look, just imagine TOS looked like this, just like Roddenberry told us to imagine the TOS Klingons look like TMP Klingons.
The bottom line for me is simple:
The DSC story is intended to lead us to TOS; therefore it is the same universe as TOS, overlooking the aesthetic difference in a similar manner to how we overlooked the Klingon differences between TMP to TOS.